Am'janiriSarm"}    Bleaching  Powder  and  Analogous  Compounds.  9 
hours,  the  clear  liquid  is  decanted,  the  alcohol  distilled  off,  the  remain- 
ing liquid  filtered  through  well-washed  animal  charcoal  and  evapo- 
rated to  dryness,  or,  when  sufficiently  concentrated,  it  is  spread  on  glass 
plates  exposed  to  a  heat  of  about  140°F.  till  it  scales.  When  thor- 
oughly dry  it  should  be  preserved  in  well-stopped  vials.  It  is  given 
in  doses  of  5  to  10  grains,  in  the  form  of  pills,  as  it  is  too  unpleasant 
for  any  other  form  of  exhibition.  This  method  of  dessication  is  quite 
important,  as  the  preparation  becomes  very  tough  if  dried  in  mass. 
IMPURITIES  IN  CHLORIDE  OF  BARIUM. 
By  A.  E.  Brown. 
Read  at  the  Pharmaceutical  Meeting,  December  18,  1883. 
While  making  a  quantitative  analysis  of  chloride  of  barium  which 
had  been  sold  as  chemically  pure,  I  found  a  deficiency  of  more  than  2 
per  cent.,  each  successive  analysis  producing  the  same  result.  A  qua- 
litative analysis  for  impurities  was  made  as  follows :  to  a  concentrated 
solution  of  the  salt  was  added  chloride  and  hydrate  of  ammonium, 
when  hydrate  of  aluminium  was  precipitated.  No  other  impurities 
were  found. 
A  quantitative  analysis  of  the  salt  now  showed  that  it  contained 
2*23  per  cent,  of  chloride  of  aluminium.  The  formula  BaCl2.2H20 
requires  Ba  56-16,  CI  29'09,  or  BaCl2  85'25  per  cent.;  H20  14-75  per 
cent.;  total  100.  The  result  of  the  analysis  was  BaCl2  82*61,  A12C16 
2  23,  H20  14-75  per  eent;  total  99-59. 
BLEACHING  POWDER  AND  ANALOGOUS  COMPOUNDS. 
By  G.  Lunge  and  P.  Naef. 
As  Kraut  has  recently  taken  up  the  subject  of  the  constitution  of 
bleaching  powder,  directing  a  polemical  paper  against  the  investiga- 
tions of  Lunge  and  Schaeppi  ("Amer.  Jour.  Phar.,"  1881,  p.  608),  the 
authors  have  repeated  their  former  experiments,  and  those  of  Kraut, 
with  a  view  of  establishing  the  correctness  of  the  formula  Cl.Ca.OCl 
first  proposed  by  Odling.  In  their  former  paper  great  stress  was  laid 
on  the  complete  and  ready  expulsion  of  all  the  chlorine  in  bleaching 
powder  by  carbonic  anhydride  in  the  presence  of  a  little  moisture,  as 
militating  against  the  presence  of  free  calcium  chloride.    Kraut  has 
